Yep most of them can have their hotmirror removed, probably Nikons too. Sometimes you need to replace the hotmirror with glass from a microscope slide but otherwise its not all that hard I hear. I just dont mess with the inside of cameras due to their flash capacitor, a risk of shock. So I just paid LifePixel to do it for me.
RE: Diana F+, Europe, Part 8 (Paris)